The invention relates generally to transducers.
Structures used in aerospace applications such as aircraft components typically have integrated sensors and actuators. The actuators are used to drive electric valves, pumps, jacks, and other devices used in normal aircraft operation. Additional electronic devices may be used for avionics, surveillance, jamming, communication, or other functions. Each of these electronic devices typically has at least one current or voltage sensor. Such sensors can monitor the power consumption and indicate if there is a problem or failure of a particular device. Many motor drives for actuation on avionic or other applications include closed loop control embodiments that depend upon sensing current, voltage, or a combination of current and voltage.
In conventional aircraft systems, the output of the current and voltage sensors is linked to a flight control computer or other control electronics equipment through a wire harness with each one wire being connected to one respective sensor. In some aircraft systems, hundreds of sensors have hundreds of wires that link them to the data acquisition system. The wire harnesses have evolved over time and become extremely complex and difficult to design, manufacture, debug, and repair. Also, although a single wire has only a small amount of copper, the weight from hundreds of wires is significant and impacts the performance of the aircraft. The copper wire connecting the sensor to the digital signal processing system additionally tends to acts as an antenna for undesirable electromagnetic radiation.
It would therefore be desirable to reduce the weight and provide immunity to radiation associated with conventional aircraft control embodiments.
Current sensing is an important component of power utility distribution systems for metering and monitoring of line currents. In these systems, the currents to be monitored are at very high voltage potentials with respect to ground. The conventional systems include a current transducer with significant insulation between the line potential and the near-ground potential of the control electronics. These transducers are costly, heavy, and sometimes result in system failures.
It would therefore be desirable to isolate a current sensor at line potential from the control electronics at earth potential without heavy and costly insulation.